If a business person is to learn one chinese dialect, which would it be: Mandarin or Cantonese?

It is best to learn Mandarin, as Mandarin is the primary language spoken in Beijing and major port cities in China, such as Shanghai.

I would argue Mandarin since it is the national language in China. Cantonese is mostly spoken by people from the Canton Area (Southern China) and Hong Kong. Since China is made up of so many other dialects, Mandarin is used as the unifying national language. If you speak Mandarin, you can probably communicate with the larger population. If you are in HK, most people do not speak Mandarin there (often only Cantonese). So if you are going to do business mostly in the mainland area, I would suggest learn Mandarin. If you do most of your business in the Hong Kong (or Southern China region like Guangzhou or Shenzhen), then perhaps you should learn Cantonese instead.

Have fun!

Hm. Mandarin is the official language, yet Cantonese is the one more widely spoken by the general population. In addition, many foreign businessmen (any country) know at least a little English.

I'd say both. Sorry.

Mandarin.

i'll say mandarin, cuz it's the official language of china and it's easier to learn than cantonese

I would say Mandarin, it is more widely spoken and the official language of China, so i assume it is the most important.

Monty, what is your problem and how is it a dumb question?

Mandarin obviously because it is more widely used.

Mandarin. Spoken by all educated Chinese people. Just like English here. Not spanish. Cantoese is popular in certain area like Hong Kong, Taiwan, Quan Zhou, Fu Jing some provinces.

To get this clear:

Mandarin is a language

Cantonese is dialect

It is two different thing

For mandarin you may use it in Asia so that's additional language to learn

Cantonese is dialect therefore widely use in Hong Kong but that does not mean you may use it in all part of Asia because not all Asian knew how to speak Cantonese

Because in Asia we have different dialect we have

Hokkian , Teochew , Hokchiew , Hakka etc...

If you want you learn mandarin because Asian speak

mandarin more than their own dialect

You are misusing the word dialect. Neither of these is a dialect. They are quite distinct languages. Cantonese is far, far more useful if you are doing business with Hong Kong or Guangzhou. Mandarin is far, far more useful elsewhere in China or in Taiwan.

The answer will depend upon where specifically you will do business.
Mandarin is much more useful and is much more universally used. In the PRC, Mandarin is literally called "the common language", Cantonese is literally called "the language of Guangdong (province)"
Almost all speakers of Cantonese in China also speak fluent Mandarin. But...most speakers of Mandarin in other parts of China cannot understand a word of Cantonese. Only in Hong Kong is there less Mandarin, but in recent years they have been learning it. And almost all Hong Kong businessmen speak English (since it was a British colonly). Also, the Cantonese speakers in Malaysia will almost all speak Mandarin well.
Nobody in Taiwan speaks Cantonese. Only Mandarin and Taiwanese (or perhaps Hakkanese)
.
To sum up, you get way more coverage with Mandarin. Plus it is comparitively easier to learn.

Good luck!

what a dumb question are you a curry muncher arse wipe

Mandarin is considered the more universal of the two, altho' some people would say it all depends on what part of China you're doing business. Really, tho' most people who speak one probably speak the other, so I would say you would be safe to stay with Mandarin.

For businessmen is Mandarin, for street vendors in Hongkong, Guangzhou and Shanghai is Cantonese.

Cantonese is hust a dialect spoken in Hongkong, Shanghai, and that area, it's not taught in schools. Mandarin is taught in Chinese schools all over China, Taiwan, Hongkong, Macau, Singapore, Malaysia...
And Madarin is official while Cantonese isn't.